Juniper Research has published a new report that finds that the increased use of touchless payment services using fingerprint readers will push the number of biometric authenticated transactions to nearly 5 billion by 2019, driven by Apple Pay and Samsung Pay.

According to the report’s author, the level of security of these biometric transactions depends on how well the fingerprint data itself is protected.

“When a password or PIN is hacked, the consumer can simply get a replacement,” said Windsor Holden, author of the report and analyst at Juniper Research. “When biometric data–fingerprint, iris [scans], facial [telemetry]–is stolen, the consumer’s online identity could be irretrievably compromised.”

The report also states that the growing number of retail store locations using contactless credit card systems and mid-range smartphones with built-in fingerprint scanners, will drive the increase in biometric payments.